Electric safety-fuse or cut-out.



No. 737,368. PATENTED AUG. 25, 1903. L. W. DOWNBS. ELECTRIC SAFETY FUSE0R GUT-OUT.

APPLIOAHON FILED JUNE 2, 1900. N0 MODEL.

2 SHEETSSHEET 1.

1n venZor THE NORRIS PETERS cu, momuma, wnsumurpm n, it.

PATENTED AUG. 25, 1903 L. W. DOWNES.

ELECTRIC SAFETY FUSE 0R GUT-OUT.

urmomron nun mm 2, 1900.

z BHEETS-SHEET 2.

N0 MODEL.

Wdfiweises. M in/Cw w: Norms r z'rcas cu. PHOTO-LITHO" wnsnmowm u p.

UNITED STATES Patented August 25, 1903.

PATENT OFFICE.

LOUIS W. DOWNES, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO THE D & WVFUSE COMPANY, OF PROVIDENCE, RHODE ISLAND, A CORPO- RATION OF RHODEISLAND.

ELECTRIC SAFETY-FUSE OR CUT-OUT.

SPECIFICATION forming part of Letters Patent No. 737,368, dated August25, 1903. Application filed June 2, 1900'. serial N 1 8,84=1- (No m d l)To all whom it may concern:

Be it known that I, LOUIS W. DOWNES, a resident of Providence, RhodeIsland, have invented a new. and useful Improvement in ElectricSafety-Fuses or Cut-Outs, which invention is fully set forth in thefollowing specification.

It has heretofore been proposed to em ployincombinationwithaninclosed'mainfuse-wireor fusible metallic link asmaller auxiliary fusewire connected in the circuit parallel with themain fuse and of such capacity as to be fused at about the same time orimmediately after the main fuse-wire becomes disrupted, said auxiliaryfuse extending throughout its length along the exterior surface ofthecasing and serving to indicate by its own condition whether or not themain fuse has been disrupted. Various other arrangements of theauxiliary fuse-wire are possible, the object in every case being toafford, by reason of the auxiliary fuse-wire, an exterior visualindication of the condition of the inclosed main fuse-wire; but in theconstructions heretofore proposed and used the indication intended to bethus afforded has not been so readily discernible as is desirable andmore or less close inspection has been necessary to determine the same.

According to my present invention I provide means, in conjunction withthe auxiliary fusewvire, whereby there will be effected at the exteriorsurface of the inclosed fuse a readily-discernible and unmistakablevisual indication of the disruption of the main fuse wire or link. Thesemeans consist principally of a material or composition in contact withthe auxiliary fuse-wire and adapted to be heated thereby upon disruptionof the fuse, thus affording the desired indication either by change inits appearance or by discoloring, charring, or blackening of a labelapplied to the casing, or by both.

Theimprovements constituting this invention will be best understood byreference to the accompanying drawings, showing the same applied tovarious arrangements of the auxiliary fuse-wire.

In the drawings, Figures 1, 4, 5, 7, and 8 are longitudinal sectionalviews, each showing a different arrangement of the auxiliary fuse-wire.Fig. 2 is a plan View of the construction of Fig. 1; Figs. 6 and 9,similar views of the constructions of Figs. 5 and 8, respectively; andFig. 3 is a detail of the paper label of Fig. 1.

Except for the auxiliary fuse-wire and its accessories the constructionof the fuses illus trated in the drawings is substantially the same asthat of my Patent No. 569,373, Abeing a tubular casing, preferably of afibrous material; B B, metallic caps secured over opposite ends of thecasing and having slits or perforations b, through which vapors or gasesevolved in the casing may escape to prevent explosion or blowing open ofthe fuse-casing; C C, terminal brackets secured to the caps; D, a mainfuse-Wire connected between terminal brackets O C and passing throughthe interior of the casing; E, an air-space about the fuse} wire atabout the center thereof, said air-space being formed by a perforatedpaper-drum e.

F is a filling of a suitable material, preferably in a finelydividedstate, such as slaked lime, the principal function of which is todissipate the heat from those portions of the wire which come directlyin contact there-.

with, thus causing the rupture to take place at that part of the fusewhich penetrates the airspace, and, furthermore, said material providesa multitude of minute paths or interstices for the escape of the vaporor gas evolved upon the fusing or blowing of the main fuse D.

While I have herein illustratedthe improvements constituting my presentinvention in conjunction with the particular construction of fuse setforth in my patent referred to, it is to be understood that theinvention is equally capable of use in other constructions of fuses.

Referring now to Fig. 1, G represents the auxiliary fuse, consisting inthis instance of a fine wire of German silver'or other suitable metalthreaded through two small openings 9 g, formed through the casing A atabout the center thereof. A short portion or part h of the wire is thuscaused to lie against the outer surface of the casing A, the oppositeends of the wire being carried along the inner surface of the casing incontact with the filling F and out of the open ends thereof. Theextremities of the auxiliary fuse-wire are finally bent over against theouter surface of the casing, as clearly shown at t' z'. The metalliccaps B 13 press against and make electrical contact with extremities 2'i, thus forming between the terminals 0 G a second path for the currentby way of the auxiliary fuse parallel to the main fuse. Z is a materialin contact with the portion h of the auxiliary fuse-wire adapted to besufficiently heated thereby upon disruption of the fuse to afford thedesired indication either by change in the appearance of the material Zwhen the same is exposed to View, as shown in the drawings, or bydiseoloring, charring, or blackening of a paper label K by the heat ofmaterial Z, or by both. The label K, of paper or equivalent material, ispasted or cemented to the surface of casingA aroundthe material Z and isshown as having an opening therein in which said material is located andthrough which it is exposedto view. Any suitable material Z may beemployedfor example, sulfo-cyanid of mercury, which may be mixed withwater and mucilage and applied in the form of a thick paste in asemiliquid or plastic state. It subsequently dries and hardens.

The operation of the fuse of Fig. l is as follows: Current of normalstrength passes through the fuse Without afiecting the fusewires, thelarger portion of the current being of course carried by the main fuseD. Upon thecurrent becoming abnormal main fuse D will be at oncedisrupted at the air-space E, thus throwing the entire charge ontoauxiliary fuse G. As the filling F serves to dissipate to a considerableextent the heat generated by the abnormal current in those parts of theauxiliary fuse which are in contact therewith, the heating of said fusebecomes most intense in the portion h thereof, instantly melting thesame and heating the sulfo-cyanid of mercury Z, causing it to char andblacken or/discolor that part of the label which is subjected to theheat and exude in bubbles and change its color, (from a whitish to abrownish hue,) thus indicating that the fuse has been burned out.

The advantage of this device over similar devices heretofore known to meis the entire absence of any discharge in the shape of a flash or ofburning on the surface of the tube or casing, the fine auxiliaryfuse-wire being completely incased in material which prevents such adischarge. Furthermore, the disruption being confined by reason of theheat-dissipating action of the filling F to short portion h of the fusewhich lies outside of the casing A the sparking or burning, if any,would necessarily be so slight as to cause no possible danger or injury,the condition of the fuse being nevertheless readily perceptible. Anysuitable form and arrangement of auxiliary fuse may be employed forheating the material Z upon disruption of the main fuse.

In the modification illustrated in Fig. 4 instead oflacing the auxiliaryfuse-wire through two perforations in the casing the loop h(corresponding to part 7?. of Fig. 1) projects outwardly through asingle opening 9' in the casing. In other respects the construction isthe same as that of Fig. 1. The operation is also substantially thesame.

In the fuse shown in Figs. 5 and 6 the openings g g in the casingthrough which the auxiliary fuse-wire is laced are farther apart thanthe corresponding openings of Fig. 1, thus causing a longer portion orpart h of the fuse-wire G to extend along the outside of the casing. Inthis case the paper strip K, which is applied to the casing withadhesive material, covers the part h of the fuse-wire, except at theelongated opening 7c, where it is covered by a suitable material, suchas sulfo-cyanid of mercury, as before. The operation of this form of thefuse is substantially the same as that above described.

The fuse illustrated in Fig. 7 is the same as that of Figs. 5 and 6,with the exception that instead of the opposite ends of the auxiliaryfuse-wire extending from the openings 9 9 along the inner surface of thecasing to contact with the caps B B said ends are carried downwardlythrough the filling F and joined to the main fuse-wire D at points d don opposite sides of drum 6. The operation of this form of fuse issubstantially the same as that of the others.

In Figs. 8 and 9 I have illustrated one manner of employing the materialZ with an aux iliary fuse-wire which extends entirely along the exteriorof the casing. Referring to said figures, the auxiliary fuse-wire G(including the short portion or part to which material Z is applied)extends along the upper side of the casing A from end to end thereof.The terminal caps B B press tightly against and make electrical contactwith the ends of said fuse-wire. Over that part of fuse-wire G whichlies between the caps there is placeda covering-K preferably of heavypaper,which is secured to the outer surface of the casing Aby anysuitable adhesive material. An elongated opening 70 may be formed in thepaper over the middle of the fuse-wire and about the material Z.

In fuses embodying the invention herein described the relativecapacities of the main and auxiliary fuse-wires may be such that saidfuses will be simultaneously disrupted on the passage of an abnormalcurrent, the auxiliaryfuse serving merely to efieet the indication aboveexplained and performing no function in the prevention of an are or thedisruption of the main fuse, or the relative capacities of thefuse-wires may be such that the main fuse-wire becomes disrupted first,the auxiliary fuse-wire by momentarily carrying the whole charge actingin a Well-known manner to prevent arcing at the main fusewire. In thelatter case the auxiliary fusewire would serve the double function ofeffecting an indication of the condition of the fuse and of preventingarcing.

In employing herein the term fuse-wire in referring to the severalfuse-links I intend by said term to include links of any suitableformsucl1, for example, as metallic strips or bands.

What I claim is 1. In an electric fuse or cut-out, a casing, a mainfuse-wire inclosed by said casing, an auxiliary or indicating fuse, anda suitable material applied, in a semiliquid or plastic state, intocontact with the auxiliary fuse and adapted upon disruption of thelatter to be heated to afford at the exterior surface of the device avisual indication of the condition of the main fuse-wire.

2. In an electric fuse or cut-out, a casing, a main fuse-wire inclosedby said casing, an auxiliary or indicating fuse, and a suitable materialapplied, in a semiliquid or plastic state, into contact with theauxiliary fuse said material being located at the exterior surface ofthe casing and adapted upon disruption of the auxiliary fuse to beheated to afford at the exterior surface of the device a visualindication of the condition of the main fusewire.

3. In an electric fuse or cut-out, a casing, a main fuse-wire inclosedby said casing, an auxiliary or indicating fuse-Wire, and a suitablematerial applied, in a semiliquid or plastic state, into contact with apart of the auxiliary fuse-wire at the exterior of the casing andadapted upon disruption of the auxiliary fuse-wire to be heated, thusaffording at the exterior of the device a visual indication of thecondition of the main fuse-wire.

4. In an electric fuse or cut-out, a casing, a main fuse-Wire inclosedby said casing, an auxiliary or indicating fuse-wire outside of andextending along the exterior surface of the casing, and a suitablematerial applied, in a semiliquid or plastic state, into contact withthe auxiliary f use-wire and adapted upon disruption of said wire to beheated to afford at the exterior of the device a visual indication ofthe condition of the main fuse-wire.

5. In an electric fuse or cut-out, a casing, a main fuse-wire inclosedby said casing, an auxiliary or indicating fuse-Wire, a suitablematerial in contact with the auxiliary fusewire and adapted upondisruption of the latter to be heated, and a label applied to thesurface of the casing in association with the material and adapted to bediscolored by the action thereof upon disruption of the auxiliaryfuse-wire.

6. In an electric fuse or cut-out, acasing, a main fuse-wire inclosedbysaid casing, an auxiliary or indicating fuse-wire, a suitable materialapplied to the casing in contact with a part of the auxiliary f use-wireat the exterior of the casing and adapted upon disruption of the latterto be heated, and a label applied to the surface of the casing inassociation with the material and adapted to be discolored upondisruption of the auxiliary fusewire.

7. In an electric fuse or cut-out, a casing, a main fuse-wire inclosedby said casing, an auxiliary or indicating fuse, a suitable material incontact with the auxiliary fuse and adapted upon disruption of thelatter to be heated, and a label applied to the surface of the casing inassociation with the material and adapted to be charred or blackened bythe heat of said material upon disruption of the auxiliary fuse.

8. In an electric fuse or cut-out, a casing, a main fuse-wire inclosedby said casing, an auxiliary or indicating fuse-wire, a suitablematerial applied to the casing over a part of the auxiliary fuse-wireand adapted to be heated upon disruption of the same, and a labelapplied to the exterior surface of the casing in association with saidmaterial and adapted to be charred or blackened by the heat of the sameupon disruption of the auxiliary fuse-wire.

9. In an electric fuse or cut-out, a casing, a main fuse-wire inclosedby said casing, an auxiliary or indicating fuse-wire outside of andextending along the exterior surface of the casing, a suitable materialapplied to the casing over a portion of the auxiliary fusewire andadapted to be heated upon disruption of the latter, and a label appliedto the exterior surface of the casing over the auxiliary fuse-wire andassociated with said material whereby the heat thereof upon disruptionof the auxiliary fuse-wire will char or blacken the label or partthereof.

10. In an electric fuse or cut-out, an enveloped main fuse-wire, anauxiliary fuse, and a material applied in a semiliquid or plastic stateinto contact with said auxiliary fuse and adapted to change color upondisruption of the auxiliary fuse-Wire.

11. In an electric fuse or cut-out, a main fuse-wire, an inclosingcasing therefor, an auxiliary or indicating fuse-wire, and a covering ofsuitable material applied to a part of the auxiliary fuse-wire at theouter side of the casing and adapted to change color upon disruption ofsaid auxiliary fuse.

12. In an electric fuse or cut-out, a main fuse-wire, an inclosingcasing therefor, an

auxiliary or indicating fuse-wire and a label I applied to the surfaceof the casing and having an opening therein beneath which opening theauxiliary fuse-wire extends along the surface of the casing.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

LOUIS W. DOWNES.

Witnesses:

JAMES H. THURSTON, IRA L. FISH.

